Machine for grinding cement



(No Model.) I

' B; F. HOLLAND.

MACHINE FOR GRINDING CEMENT.

No. 244,994. Patented Aug. 2,1881.

' use and the object thereof is to provide asim-- To all whom it may concern v UNITED STATES PATENT OFFICE.

BENJAMIN'F. HOLLAND, OF UTIOA, ILLINOIS.

MACHINE FOR G RI'NDING CEMENT.

SPECIFICATION forming part of Letters Patent No. 244,994. dated August 2, 1881.

Application filed June 4, 1881.

Be it known that I, BENJAMIN F. HOLLAND,

citizen of the United States, residing at Utica,

in the county of La Salle and State of Illinois,

have invented certain new and useful Im provements in Machines for Grinding Oement; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawing, making apart of this specification, and to the letters and figures of reference marked thereon.

The presentinvention has relation to certain new and useful improvements in machines for grinding cement to a fineness required for ple device or machine that can be constructed at a comparatively small cost, not liable to get out of order, and will with rapidity reduce the particles of cement to a very fine powder necessaryfor mixing.

Heretofore this class of machines for grindin g cement or clay consisted of arevolving pan or table for receiving the material to be ground, which was reduced to fine particles by crushin g-rollers revolving around a stationary and horizontal shaft. Although the'material was reduced to the necessary fineness, there were no means of separating the finerparticlesfrom the coarser while the process of grinding was going on, the pan having a solid or closed bottom.

Another form of machine has been in use in which the pan or table, although provided with a perforated bottom, was stationary, while a shaft carrying crushing-rollers horizontally revolves around the pan or table, the rollers at the same time revolving upon their own axis. This pan or table, being stationary,

would not act as a sifter for the cement, the

passage of the finer particles through the perforations depending entirely upon the action of the shaft and rollers, which was not sufficient, the result being the occasional clogging up of the perforations, and thus rendering the machine to a certain extent impracticable.

' The object of the'invention is to removethese objections by providing the pan' with a perforated bottom and connecting it with suitable mechanism whereby it is given a horizontal rotary motion to sift the particles as they-are re- (No model.)

duced to the required fineness through the perforated bottom, and, as previously stated, render the machine practicable and effective. These objects I attain by the construction substantially as shown in the drawing and hereinafter described.

1n the accompanying drawing, which shows a perspective view of the machine, A represents the frame, of any suitable construction, to which is connected the vertical shaft a, the upper end thereof having its bearings in the cross-beam of the frame, and the lower end resting in a step, b, which is preferably made adjustable vertically by set-screws 0, so as to accommodate it to the wearing of the end of the shaft 1). r This shaft has connected to it a pan, B, with perforated bottom (I, said pan, if desired, being secured to the shaft by a set screw, and collar formed around the central opening through which the shaft passes.

The shafte is formed with a yoke, f, through which passes the shaft a,thus assistingin supporting said shaft in a vertical or upright position.

To the upper end of the shaft 0. is keyed a bevel-gear wheel, g, for engaging with a similar wheel, h, upon the end of a horizontaldriving-shaft, 6, receiving its motion from suitable gearing of an engine or other power.

The panB being filled with the desired quantity of cement, and the shaft caused to rotate by the gearing g h, as the pan turns with the shaft it causes the rollers O to revolve in opposite directions by the frictional contact with the cement, which crushes it to atoms, and when reduced to the required fineness it falls through the perforations in the bottom 01.

If desired, the cement may be a second time subjected to the grinding process, or as often as found necessary, and may be dumped into the pan by a suitable elevator or any other means found preferable.

The rollers C may be of any desirable width and size. It is preferred, however, that their periphery be as broad as possible, so as to have as great an area of surface from the center to the periphery'or rim of the pan as possible to facilitate the process of grinding.

Having now fully described my invention, what I claim as new, and desire'to secure by Letters Patent, is-- In a machine for grinding cement, the com- In testimony that I claim the above I have bination, with the stationary horizontal shaft hereunto subscribed my name in the presence 0, carrying revolving rollers O, of any suitable of two witnesses.

diameter and width, of the horizontally-re BENJAMIN F. HOLLAND. 5 volving pan B, provided with the perforated Witnesses:

bottom d, substantially as and for the purpose H. W. HIGBY,

set forth. 0. A. GoLLINs. 

